Compositions, methods and kits for treatment of diabetes and/or hyperlipidemia are provided herein. Such compositions can contain synergizing amounts of leucine and/or one or more leucine metabolites in combination with nicotinic acid, nicotinamide riboside and/or nicotinic acid metabolites, and with at least one or more anti-diabetic agents. Such compositions can contain sub-therapeutic amounts of nicotinic acid, nicotinamide riboside and/or nicotinic acid metabolites, and/or sub-therapeutic amounts of one or more anti-diabetic agents that can achieve the same therapeutic efficacy as therapeutic amounts of said compositions in diabetes and/or hyperlipidemia medicaments. The composition can also reduce the side effects associated with treatment using anti-diabetic agents and/or nicotinic acid.
